A SMR PWR Reactor Core Design Using Nitride Fcm Fuels With Fecral Cladding and Forced Convection Circulation

Abstract

In this work, a SMR (Small Modular Reactor) core based on the current PWR technology is designed and analyzed from view point of core physics. The core thermal output is 330MWt which is the same as that of the SMART reactor core while the new core uses 13x13 fuel assembly containing 9 larger water holes for control rods and instrumentations and the fat FCM fuel rods of nitride fuel kernels to fully utilize the superb features of FCM fuels in PWRs. In particular, we considered new BP (Burnable Poison) rods in which the Er₂O₃ BP material is admixed with SiC matrix of FCM fuel. Higher uranium enrichments of 14 wt% and 17 wt% than the commercial PWR cores were required to achieve long cycle length of ~2 EFPYs with small initial heavy metal inventories in the FCM fuels and large neutron leakage in the SMR core. The reload core analysis from the initial to equilibrium cycles shows that the reload cores have cycle lengths ranging from 726 EFPDs for initial core to 734 EFPDs for equilibrium cycle, sufficient shutdown margins and the desirable safety-related parameters. An average discharge burnup of 98 MWD/kg for the equilibrium cycle was achieved. This is much larger than a similar natural convection core design (74MWD/kg), described in a comparison paper in this conference.